Felt manufacture



April 15, 1930. v. A. WALLIN I FELT MANUFACTURE Filed March 29, 1928INVENTOR.

A TZ'ORNE Y.

Patented Apr. 15, 1930 UNITED STATES PATENT OFFICE VAN A. WALLIN, OFCHICAGO, ILLINOIS, ASSIGNOR T AMERICAN HAIR 8: FELT COM- PANY, OFCHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS FELT MANUFACTUREApplication filed March 29, 1928. Serial No. 265,598.

The invention relates to felt manufacture.

In the ordinary and usual process of manufacturing soft felts, such asare used for heat and cold insulation, cushioning and similar purposes,by the laid felt process where coarse fibres are used, such as hair andjute, and particularly in the process of manufac' turing soft hair-felt,it is impracticable to manufacture successfully a thin sheet of felt,

10 that is, a felt whose thickness is much below a quarter of an inch.This is due to the fact that soft felts, made of coarse fibres such ashair and jute, are of necessity low cost products made to compete withother cheap cush- 5 ioning and heat insulating materials, such as flax,straw, wood fibre and cotton linters. To reach these low costs thefibres must be picked, carded, formed into bats and compacted or feltedwith heavy, coarse, mechanical equipment, including cards, lappers,platens,

etc., designed to handle fibres in large quantities, such equipmentdiffering very materially from the similar but finer and lightermachinery of much smaller capacity used in tl1e manufacture of highergrade materials,

such as fulled hair felts, cotton felts and wool felts. The lighter,finer machinery is designed to handle thin felt while the heavyequipment is designed to handle coarse materials made into thick felt. V

In the use of this coarser machinery it is impracticable to lay a thinbat of hair or jute or other feltable fibres under the usual methodswith sufficient uniformity to produce a marketable piece of felt. Thebat, in the process of manufacture, is subjected to heavy pressure andviolent vibrations, which are essential to the massive felter platesused in the manufacture of relatively thick insulating hair felts andother soft felts made of similar coarse materials. The pressure and thetearing action due to the weight and agitation of the platens or feltplates tend to destroy the thin bat instead of compacting it, theresulting products being liable to be torn or broken, or very uneven inthickness and, as stated, in common practice no attempt is made toproduce thin felts through the use of the ordinary large size mechanicalequipment built for the manufacture of soft hair Q for successfullymanufacturing thin felts with the heavy, coarse machinery used in themanufacture of thick felts.

In the drawings Fig. 1 is a view through a felting apparatusillustrating my method, parts being broken away;

Fig. 2 is a detail end view of the material at an intermediate stage ofmanufacture.

I have discovered that the unsatisfactory product resulting in anattempt to manufacture thin felt by the use of heavy felting equipment,such as the fixed platen 3 and the vibratory felter plate 4 can beavoided by laying two or more thin bats 5 together one above the otherwith a separator 6 between the same, placing these bats with theinterposed separator between the platen 3 and the plate 4 and subjectingthe several layers to the pressure and vibration of the felter plate atone operation. The effect of the several layers of superimposed bats andseparator or separators is to cushion each other from the disintegrationthat results when a single thin bat is placed under the felter platealone. After the several layers or bats have felted or hardened underthe felter plates, by the method above described, they are separatedinto individual units merely by peeling off the top bat 5 or sheet offelt and then alternately peeling off the intervening separator 6 andthe sheets 5 of felt as they are exposed. These thin felt sheets 5 maythen be dried, trimmed and cut as desired. The separator 6 may be of anysuitable thin material capable of transmitting the vibratory pressureand preventing undue adhesion or penetration of the feltable fibres toor into its faces and I prefer to use fine mesh burlap, muslin, sheetingor paper for this purpose.

What I claim as my invention is:

The method of producing felts, made of hair, jute or other coarse,feltable fibres, too i thin to be felted between the felter plates ofthe usual heavy felting machine, which consists in building up acomposite mass of thin bats of the feltable fibres, separated from eachother by a single, thin, flexible separator, to a thickness sufficientfor eflicient handling in the usual heavy, coarse, felting machineryused in the manufacture of thick felts, subjecting the com osite mass tothe pressure and agitation 0 the felter plates at one operation, andafter felting removing the separators.

In testimony whereof, I a-flix my signature.

VAN A. WALLIN.

